When Leslie Hall came across a rock painted with the words “Kind Soul,” she had just finished a chemotherapy treatment for breast cancer. The rock, which she found in a grocery store parking lot, offered some comfort. It was a random act of kindness that made her smile.

A few days later, when she found a second rock bearing the message, “You are loved,” it had an even bigger impact.

“It reminded me that I am loved and I am a good person and I will get through this,” said Hall, who lives in Cape Cod, Mass. “It also helped me see all the kindness around me — all the good that my caregivers and doctors had shown me. It reminded me of the times when strangers who noticed my bald head or scarf gave me a hug.”

Hall was inspired. She decided to start painting rocks in hopes of spreading kindness to others. She found it therapeutic. She reached out to Megan Murphy, a fellow Cape Cod resident and founder of The Kindness Rocks Project.

For years, Murphy had walked the beach looking for heart-shaped rocks and pieces of beach glass. When she found them, she considered it a sign that her deceased parents were watching over her. A few years ago she started writing messages on rocks and leaving them on the beach because she noticed others who seemed to be searching for a message or sign. She wrote positive messages, inspirational quotes and song lyrics on the rocks.

“I thought about, what’s the message that I would want to find?” she said. “I used anything that would spark something.”

Later she added hashtags on the rocks directing people to a website and Facebook page explaining the rocks are intended to spread joy and goodwill. “It’s a simple way to put good out there. It builds community,” Murphy said. “People feel good when they’re doing it. It’s just this magical thing.”

She and her followers began organizing rock-painting parties and leaving rocks in parks, on sidewalks and at parking lots. They have created “rock gardens” containing dozens of rocks that are there for the taking. Not every rock is painted with a saying. Some have drawings of flowers, happy faces or other feel-good images.

Murphy’s efforts have inspired hundreds of people in other cities and states to paint rocks and create Facebook pages encouraging kindness. Similar efforts seem to have sprung up in other parts of the country as well.

Wendy Gallacher started Fayette Rocks after learning about painted rocks from relatives in Lakeland, Fla. Her community outside of Atlanta was quick to embrace the project. “It’s basically community service, doing something good for other people,” she said. “One rock can change the way your day is going.”

Peachtree City public information office Betsy Tyler worked with Gallacher to create a rock garden near a series of city trails. Locals routinely post about how finding the rocks brightened their day, she said.

“As negative as things have gotten nationally, it never hurts to have this spark of kindness,” Tyler said.

Hall, who has been cancer-free for more than a year, credits the rock-painting project with helping her fight the disease, and she’s still amazed by its impact. Recently, while adding rocks to a garden, she was approached by a woman who asked if she could take one because the wording on it spoke to her. “She said, ‘My husband died two weeks ago, and I feel like it’s a message from him,’” Hall said.

Moments later another woman came by and selected a rock. She told Hall the rock’s message, “Stars can’t shine without darkness,” was something she wanted to share with a sick friend.

Time and again the rocks seem to convey the right message to the right person, said Charity Blair, who started a rock project in Jefferson City, Mo.

“Sometimes you find the perfect rock at the perfect time with the perfect message,” Blair said. “It just lets you know everything is going to be OK.”

The Kindness Rocks Project website shows rocks with inspirational messages have been left in Lahaina, Ewa Beach and Waikiki. Download a “how-to” guide at thekindnessrocksproject.com.